1. Field of the Invention
This patent relates to an apparatus for evaporating waste liquids. More particularly, this patent relates to a portable evaporation chamber for use in disposing of wastewater from oil and gas drilling and production operations.
2. Description of the Related Art
In most oil and gas drilling operations, drilling fluid or mud is used to remove drill cuttings from the borehole. The drilling fluid is usually a mixture of clays, chemicals, weighting material and water or oil. The drilling fluid generally is pumped from a mud pit to a standpipe, through a kelly hose to a swivel, through the kelly and down into the drill string to the bit. From there the fluid and cuttings flow back up the annular space around the drill string to a mud return line. From the return line the fluid passes across a shaker where the cuttings are removed and on to a reserve or pond. The pond is used to collect the excess water. Water production can continue throughout the life of the well.
The problem with this arrangement is that the collected water in the pond must be disposed of. Various evaporation systems have been devised to accomplish this task. Typically, these systems involve spraying the water into the air using high-pressure pumps and nozzle arrays that maximize the surface area of the water droplets in order to increase evaporation rates. Many of the evaporation systems are designed to evaporate the water while floating over the wastewater pond to minimize ground saturation.
These evaporation systems have several disadvantages. First, they cannot operate in high winds or extreme cold weather. Second, the mist still allows for ground saturation in areas of sustained winds which requires system shutdown. Third, these systems can be cumbersome to set up, maintain and move. Fourth, these evaporation systems are limited to impoundment pond operations. Once a drilling site has been reclaimed, the excess water ends up in a storage tank which current evaporation systems cannot access.
Thus it is an object of the present invention to provide a water evaporation system useful in oil and gas drilling operations that is easy to set up and tear down, is capable of operating in windy or sub-zero temperatures, and can be used with pond or tank operations.
Another object of the invention is to provide a water evaporation chamber that can be set up on ground near a pond or tank, and in which wastewater is atomized into 300 micron or smaller water droplets that can be carried out through the top of the evaporation chamber and evaporated in the surrounding atmosphere.
Yet another object of the present invention to provide a wastewater evaporation system that can be operated by one person.
Further and additional objects will appear from the description, accompanying drawings, and appended claims.